1. Field of the Invention
The present invention is generally in the field of electronic circuits and systems. More specifically, the present invention is in the field of communications circuits and systems.
2. Background Art
Transceivers are typically used in communications systems to support transmission and reception of communications signals through a common antenna, for example, at radio frequency (RF) in a cellular telephone or other mobile communications device. A conventional receiver typically utilizes several stages to amplify and process what may often be a weak reception signal. In the receiver “front-end,” for example, a low noise amplifier (LNA) may be used to boost the reception signal prior to down-conversion from RF to baseband by a mixer stage. In a conventional receiver “back-end,” the baseband signal is then filtered by a high-order low-pass filter (LPF), for is example a 4th-order or 5th-order LPF, which provides substantial additional gain control in the conventional receiver design.
In such a conventional receiver, for example, the gain control provided by the receiver as a whole may be primarily produced by the receiver back-end, with the high-order LPF contributing a significant portion of the overall gain. Due to the stringent requirements imposed on the high-order LPF in conventional receiver designs, however, the high-order LPF typically consumes much of the power and dominates most of the area required to implement the receiver. In addition to the LPF discussed as an example above, other blocks in the conventional receiver architecture can also contribute to undesirable power and area consumption. As communications technologies move toward ever smaller device sizes and adopt ever lower power consumption constraints, as represented by the 40 nm technology node, for example, the relative bulk and high power consumption of conventional receiver architectures have become increasingly undesirable.
Thus, there is a need to overcome the drawbacks and deficiencies in the art by providing a compact low-power receiver architecture suitable for implementation as part of a mobile device transceiver.